Here is a pix of some Panache cuttings, to show the stripes in the bark. If you are looking for a Panache and the wood is not striped, it is not Panache. These examples are quite pronounced, and some are not as vivid, but there will always be some evidence of striping. As the wood grows older, it looses the stripes, but 1st year wood will be striped. In contrast wood from the SAME tree (not grafted) which has reverted (hence my "Reverse" fig) shows no striping at all.
